In the photofinishing art, reflection and transmission densitometry is conventionally employed for calibration of the photofinishing system. In one known printer system, depicted in commonly assigned U.S. Pat. No. 4,933,710--Beaulieu et al, a photographic film scanner is provided that employs a single light sensor, or detector, for both the negative scanning and densitometry functions. However, two light sources are used in the disclosed scanner arrangement. One light source is used for scanning color negatives and for transmission densitometry measurements and a separate light source is used for reflection densitometry measurements. The use of two separate light sources is disadvantageous since it increases parts cost, power source requirements and space allocation and also requires the use of two separate sets of optical filters. It is desirable, therefore, to provide a photographic film scanner system that employs a single light source for both negative scanning and transmission/reflection densitometry.